is it possible to achieve access to USR0 or USR1 LED on Beagleboard. When I
try to make export file, I get:
-bash: echo: write error: Device or resource busy
It is because gpio-leds driver use it? The only way that it drop that pin is
Yes, I think.
removing from kernel and recompilation?
No, I think. Have you tried:
cd /sys/bus/platform/drivers/leds-gpio ; echo leds-gpio >unbind
is it possible to achieve access to USR0 or USR1 LED on Beagleboard.
Yes, using the leds-gpio driver, that gives you full control over it. incidentally, it's on by default
To be clear, you can control the LEDs either way: by using the already
loaded leds-gpio driver, or by unloading (unexporting, whatever) it
and then controlling that GPIO pin as normal.
I read some kernel documentation somewhere that said controlling the
LEDs with leds-gpio is the better way (if controlling LEDs is really
what you want). Not sure why.
This is exactly what I use: http://elinux.org/EBC_Exercise_10_Flashing_an_LED. I don’t have expansion header and my attempts to connect LED directly to the pads on board didn’t worked. But I wanted to try some things with GPIO, this is why I wanted to use LEDs on board, not just for control LEDs (what can be done by driver).
And it works:
`
cd /sys/bus/platform/drivers/
leds-gpio ; echo leds-gpio >unbind
`
After unbinding I have access to onboard LEDs
Thanks Britton, Koen, Dan for all hints.
W dniu piątek, 21 września 2012 21:10:47 UTC+2 użytkownik valdez napisał: